MC9S12T64 Datasheet, PDF (414/608 Pages) Motorola, Inc – Specification

Freescale Semiconductor, Inc.
Enhanced Capture Timer (ECT)
Pulse
Accumulators
When enabled (LATQ=1), the main timer value is memorized in the IC
register by a valid input pin transition.
The value of the buffered IC register is latched to its holding register by
the Modulus counter for a given period when the count reaches zero, by
a write $0000 to the modulus counter or by a write to ICLAT in the
MCCTL register. See Figure 69 in page 409.
If the corresponding NOVWx bit of the ICOVW register is cleared, with a
new occurrence of a capture, the contents of IC register are overwritten
by the new value. In case of latching, the contents of its holding register
are overwritten.
If the corresponding NOVWx bit of the ICOVW register is set, the capture
register or its holding register cannot be written by an event unless they
are empty (see IC Channels). This will prevent the captured value to be
overwritten until it is read or latched in the holding register.
• IC queue mode:
When enabled (LATQ=0), the main timer value is memorized in the IC
register by a valid input pin transition. See Figure 70 in page 410.
If the corresponding NOVWx bit of the ICOVW register is cleared, with a
new occurrence of a capture, the value of the IC register will be transferred
to its holding register and the IC register memorizes the new timer value.
If the corresponding NOVWx bit of the ICOVW register is set, the capture
register or its holding register cannot be written by an event unless they
are empty (see IC Channels).
In queue mode, reads of holding register will latch the corresponding
pulse accumulator value to its holding register.
There are four 8-bit pulse accumulators with four 8-bit holding registers
associated with the four IC buffered channels. A pulse accumulator
counts the number of active edges at the input of its channel.
The active edge can be programmed through the TCTL4 register (for the
8-bit pulse accumulators and the 16-bit pulse accumulator PACB) and
MC9S12T64Revision 1.1.1
Enhanced Capture Timer (ECT)
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